where \(\Delta \)  denotes the conformal dimension of the conformal field at the boundary point \(P\) .
Lines connecting bulk points represents bulk-to-bulk propagators, for which we have choosen the following representation [1]},
\(\begin{split}G^{\Delta }_{BB}(X_1, X_2) = \int _{-i\infty }^{i\infty }{\mathrm {d}c\,\mathrm {d}\gamma \over (2\pi i)^2}{\Gamma (h+c-\gamma )\Gamma (h-c-\gamma )\over \Gamma (c)\Gamma (-c)((\Delta -h)^2-c^2)}{\Gamma (\gamma )\Gamma (h-\gamma )\over \Gamma (2h-2\gamma )\,u^{\gamma }}\,,\end{split}\) 
